This SBIR Phase I project will develop a device that will perform methanol synthesis from CO2 and H2O using sunlight by mimicking the photosynthetic process taking place in plants and certain bacteria. A solar methanol biofuel generating device will be fabricated that uses a light-trapping metamaterial substrate and a bio-inspired de novo designed protein domain which will generate biofuels when modularly connected to enzyme domains directly derived from Nature. The project combines the powerful light-concentrating abilities of metamaterial composites with light-harvesting capabilities of proteins that mimic photosynthetic structures. The combination of metamaterials and light-harvesting proteins with additional protein components capable of carrying out chemical catalysis allows for the creation of inexpensive, robust and regenerative fuel cells that cycle between atmospheric carbon dioxide and methanol.
The broader/commercial impact of the project will be production of methanol in a non-expensive manner. Methanol will find applications in the biodiesel industry and thus will have a positive impact on the energy and transportation sectors.
Increasing the efficiency and reducing the cost of solar energy production and storage are two of the most important technical challenges of the 21st Century. This project takes on both these challenges with a novel combination of biotech and nanotech. Our proposed device is designed to capture and concentrate sunlight then covert it into useful chemical energy via biochemical reactions, inspired by and improving upon natural photosynthesis. Recent advances in biotechnology have made possible the human engineering of proteins, the machinery of the biological world. Natural proteins can be refined and streamlined to engineer robust, low cost systems. Our proteins self-assemble in large-batch reactions, hence the much lower production cost compared to current, commercially available solar energy materials. In our proposed device, a novel protein complex (designed from scratch) is chemically attached to a nano-scale patterned metal surface. The metal surface is designed to take advantage of electromagnetic interactions that occur at the nano-scale (Fig. 1), efficiently concentrating the light that powers the protein layer. Each protein then acts as a tiny, solar-powered chemical factory that stores solar energy in a useful form by converting atmospheric carbon dioxide into formic acid biofuel. When energy is required to power an external device, the formic acid fuel is fed into a commercially available fuel cell that produces electricity, along with the byproducts carbon dioxide and water. Our device can then transform carbon dioxide and water back into formic acid, thus recycling the by-products of energy production, as shown in Fig. 2. This carbon-neutral biofuel generator promises to be a disruptive technology with high efficiency in solar energy conversion and storage and low economic and environmental costs. In this first phase, we have designed and constructed a component of the protein complex that absorbs light and produces the excited electrons that will subsequently be used in a reaction to reduce carbon dioxide to formic acid. We verified that this component is functional, and identified strategies for further optimization. The protein was encapsulated in a protective, permeable layer, greatly increasing device lifetime. On the optics side of the project, we designed and fabricated a nano-patterned metal surface and experimentally demonstrated a significant increase in the amount of light absorbed by an attached protein. The intellectual merit of this project lies in its novelty. This will be the first functional combination of proteins designed from scratch and nano-patterned optical surfaces created for the purpose of solar energy production and storage. The broader impacts of this project lie in two areas: first in its end-product, a carbon-neutral process to convert sunlight to formic acid biofuel. Formic acid is a non-volatile fuel; it may be stored in large quantities for long periods of time and then fed into a fuel cell to satisfy high power demands. One important application of this system is a self-contained backup battery for remote cellular communication towers in developing nations where an unreliable power grid often disrupts communications. The second broad impact is in the educational opportunities provided to minority science and technology students. Our interdisciplinary research endeavor, including biophysics, biochemistry, optics, and electrical engineering, gives budding science and technology researchers the opportunity to learn in an atmosphere of collaboration between specializations, an invaluable experience applicable to the job market. The City College of New York (CCNY) is located in Harlem, on the upper west side of Manhattan. The undergraduate population of CCNY is composed of greater than 55% African American and Hispanic minority students, and the City University of New York (CUNY) system has trained more than 10% of the African American PhD Chemistry recipients in the nation.
